Workflow: iterative rigid body array/curve tweaking, is there a better way?
I quote from the Answer to the other Question (see comments above) of which mine is (sort of) a duplicate.

You need to change the Source and the Shape of the rigid body collisions.
In the physics tab of the properties panel, change the Source from "Deform" to "Final".
Only "Final" takes the modifiers in to consideration, hence your trouble.
The other setting you need to change is the rigid body collision Shape, set it to "Mesh".

This solves my problem:  as soon as I select Final, the replicated object becomes solid in RB world and I can still tweak the controlling curve to reshape and refine it, without any Ctrl-Z nonsense.